Process for breaking petroleum emulsions employing certain oxyalkylated diethylene triamines



May 14, 1957 w. J. DICKSON 2,792,359

PROCESS FOR BREAKING PETROLEUM EMULSIONS EMPLOYING CERTAIN OXYALKYLATED DIETHYLENE TRIAMINES Filed Sept. 15, 1954 BINARY REACTION PRODUCT FOR OXYETHYLATION AA M CgHqO l00lo DIETHYLENE' TRIAMINE cc no BINARY REACTION PRODUCT FOR OXYPROPYLATION INVENTOR PRGCESS FQR BREAKING PETRGLEUM EMUL- SIUN EMPLOYENG CERTAIN @XYALKYLATED DIETHYLENE TRHAMENES Woodrow J. Dickson, Monterey Park, Calih, assignor to Petroiite Corporation, Wilmington, Del a corporation of Delaware Application September 15, 1954, Serial No. 456,293

Claims. (Cl. 252-344) This invention relates to processes or procedures particularly adapted for preventing, breaking or resolving emulsions of the water-in-oil type, and particularly petroleum emulsions.

My invention provides an economical and rapid process for resolving petroleum emulsions of the water-in-oil type that are commonly referred to as cut oil, roily oil, emulsified oil, etc., and which comprise fine droplets of naturally-occurring waters or brines dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the emulsion.

t also provides an economical and rapid process for separating emulsions which have been prepared under controlled conditions from mineral oil, such as crude oil and relatively soft waters or weak brines. Controlled emulsification and subsequent demulsiiication under the conditions just mentioned are of significant value in removing impurities particularly inorganic salts, from pipeline oil.

More specifically then, the present invention is concerned with a process for breaking petroleum emulsions employing a demulsifier including a cogeneric mixture of a homologous series of glycol ethers of diethylene triamine. The cogeneric mixture is derived exclusively from diethylene triamine, propylene oxide and ethylene oxide in such weight proportions so the average composition of said cogeneric mixture stated in terms of initial reactants lies approximately within the trapezoid of the accompanying drawing in which the minimum diethylene triamine content is at least 1.75% and which trapezoid is identified by the fact that its area lies within the straight line connecting A, B, P, E. My preference by far is to use the compositions which represent less than one-half of this total area, to wit, the smaller trapezoid A, B, D. C.

It is immaterial as to whether one reacts the amine with propylene oxide first and then with ethylene oxide, or with ethylene oxide and then with propylene oxide; or, for that matter, one may employ a mixture of the two oxides, or, if desired, one may add a small amount of ethylene oxide, then propylene oxide, and then more ethylene oxide.

Referring to the hereto attached drawing it i simplified by noting that one may react diethylene triamine with enough ethylene oxide so the binary reaction product falls within the mixture identified by the line CC--DD on the extremity of the graph which shows combinations derived solely from diethylene triamine and ethylene oxide. After obtaining such binary reaction product it can then be reacted with propylene oxide so as to bring it within the area of the trapezoid A, B, F, E, or preferably within the smaller trapezoid A, B, D, C.

Patented May 14-, 1957 Similarly, one can produce a binary reaction product from diethylene triamine and propylene oxide as identified by the comparable line AA-BB and subject this reaction product to oxyethylation so as to bring the com position within the area of the trapezoid and preferably within the area of the small trapezoid A, B, D, C.

For the purpose of resolving petroleum emulsions oi the water-in-oil type, I prefer to employ oxyalkylated derivatives, which are obtained by the use of monoepoxides, in such manner that the derivatives so obtained have sufficient hydrophile character to meet at least the test set forth in U. S. Patent No. 2,499,368, dated March 7, 1950, to De Groote and Keiser. In said patent such test for emulsification using a water-insoluble solvent, generally xylene, is described as an index of surface-activity.

The above mentioned test, i. e., a conventional emulsification test, simply means that the preferred product for demulsification is soluble in a solvent having hydrophobe properties, or in an oxygenated water insoluble solvent, or even in a mixture containing a fraction of a watersoluble oxygenated hydrocarbon solvent and that when shaken with water the product may remain in the nonaqueous solvent or, for that matter, it may pass into the aqueous solvent. In other Words, although it is xylene soluble, for example, it may also be water soluble to an equal or greater degree.

For purpose of convenience, what is said hereinafter will be divided into three parts:

Part 1 is concerned with the oxyallcylation of diethylene triamine in a general way; I

Part 2 is concerned with the oxyalkylation of diethylene triamine using two different oxides, i. e., propylene oxide and ethylene oxide so as to produce derivatives falling within said compositional limits as previously described and noted hereinafter in detaii;

Part 3 is concerned with the resolution of petroleum emulsions of the water-in-oil type by means of the previously described chemical compounds.

PART 1 The oxyalkylation of amines is weil known. This applies particularly to reactions involving monoepoxides having not over 4 carbon atoms, such as ethylene oxide and propylene oxide. As to the oxyalkylation of a monoamine such as cyclohexylamine, see U. S. Patent No. 2,626,922 dated January 27, 1953, to De Groote. As to the oxyalkylation of a polyamine, see U. S. Patents Nos. 2,552,530, 2,552,531 and 2,552,534, all dated May 15, 19 51, and all to De Groote.

The oxyalkylation of an amine is comparable to other well known oxyalkylations and under certain conditions may require variation. There is no problem if the amine is a liquid or if it is xylene-soluble or soluble in an equivalent solvent, or can be melted and reacted at the melting point. In the case of diethyl'ene triamine the product is a liquid and. the oxyalkylation is comparatively simple for this reason. However, if desired one could follow substantially the same directions as if the product were a solid, for instance as in the case or" tris(hydroxymethyl)- aminomethane. The most satisfactory procedure in such instance is to use a slurry of the finely powdered material in xylene comparable to the oxyalkylation of sorbitol. As to this procedure, see Example A in U. S. Patent No. 2,552,528 dated May 15, 1951, to De Groote.

In order to illustrate why the herein contemplated compounds or said products are cogeneric mixtures and not single chemical compounds, and why they must be described in terms of manufacture, and molal ratio or percentage ratio of reactants, reference is made to a monohydric alcohol. Diethylene triamine has reactive hydrogen atoms and thus at the beginning or early stage of oxyalkylation may have as many as 5 reactive hydrogen atoms attached to either nitrogen or oxygen. Thus, for the present purpose it may be considered the same as an amine alcohol having 5 hydroxyl radicals. However, for the moment one can forget whether the hydrogen atoms are attached to nitrogen or to oxygen and for that matter the plurality of reactive hydrogen atoms and simply consider what happens when a monohydric alcohol is subjected to oxyalkylation.

. If one'selects any hydroxylated compound and subjects such compound to oxyalkylation, such as oxyethylation or oxypropylation, it becomes obvious that one is really producing a polymer of the alkylene oxide except for the terminal group. This is particularly true where the amount of oxide added is comparatively large, for instance, 10, 2t), 30, 40, or 50 units. If such a compound is subjected to oxyethylation so a to introduce 30 units of ethylene oxide, it is well known that one does not obtain a single constituent which, for sake of convenience, may be indicated as RO(C2H4O)30H. Instead, one obtains a cogeneric mixture of closely related homologous compounds in which the formula may be shown as the following: RO(C2H40)7ZH, wherein n, as far as the statistical average goes, is 30, but the individual members present in significant amount may vary from instances where n has a value of 25 and perhaps less, to a point where it may represent 35 or more. Such mixture is, as stated, a cogeneric closely related series of touching homologous compounds. Considerable investigation has been made in regard to the distribution curves for linear polymers. Attention is directed to the article entitled Fundamental principles of condensation polymerization, by Paul E. Flory, which appeared in Chemical Reviews, volume 39, No. 1, page 137.

Unfortunately, as has been pointed out by Flory and other investigators, there is no satisfactory method, based on either experimental or mathematical examination, of indicating the exact proportion of the various members of touching homologous series which appear in cogeneric condensation products of the kind described. This means that from the practical standpoint, i. e., the ability to describe how to make the product under consideration and how to repeat such production time after time without r difliculty, it is necessary to resort to some other method of description.

What has been said in regard to a monohydric compound of course is multiplied many times in the case of a compound such as diethylene triamine.

Although acid catalysts are used in oxyalkylations they are used to a lesser extent in the oxyalkylation of basic amines and the like. Under such circumstances one may have to use enough of the acidic catalyst to neutralize the basicity of the product and convert into a salt. This i not true where certain clays or prepared earths are used which act as acidic catalysts. Inany event, it is our preference to use basic catalysts such as caustic soda, sodium methylate, or the like.

PART 2 The oxyalkylation of an amine, particularly a primary amine, or secondary amine or a hydroxylated amine regardless of whether it is primary, secondary, or tertiary, is comparatively simple and has been described repeatedly in the literature.

if the product is a liquid, such as triethanolamine, one can proceed to treat with an alkylene oxide such as ethylene oxide, propylene oxide, or butylene oxide, at least in the early stages if desired without adding any' catalyst. Generally speaking, if ozyalkylation is rather extensive as in the present instance, one requires a catalyst after the initial stage and it i just as simple to add it from the very beginning.

The oxypropylation of a polyamine, such as diethylene triamine, is comparatively simple because such products or similar products are usually liquids at ordinary temperature and invariably at oxyalkylation temperatures. Indeed, the procedure is simply to'oxyalkylate without addition of any catalyst if desired and then when oxyalkylation slows up add the usual basic catalyst, such as powdered caustic soda or powdered sodium methylate. If desired, such catalyst can be added at the very beginning. It' is also desirable in such cases where exhaustive oxyalkylation is concerned to add a diluent, such as xylene,

high boiling petroleum solvent, or the like, at the very beginning. Such solvents usually are miscible but if not miscible one obtains a suspension or temporary emulsion and as soon as oxyalkylation has proceeded to even a slight degree the entire mass is homogeneous.

Specific reference. is made to the instant application which is concerned with ethylene oxide and propylene oxide or the equivalents. Actually, whether one uses ethylene oxide or propylene oxide or, for that matter, butylene oxide, one preferably starts with a polyamine suspended in the form of a slurry, an emulsion, a suspension or as a solution. There would be a slurry in event the amine is a solid and insoluble. In the present case, however, the amine is a liquid as pointed out.

. If desired, one can employ an alkylene carbonate such as. ethylene carbonate, butylene carbonate, or propylene carbonate, for the initial oxyalkylation. Where such initial oxyalkylation has gone far enough to convert the polyamine into a solvent-soluble product, i. e., soluble in xylene or an aromatic petroleum solvent, one can then use the oxides. The carbonates of course, cost more than the oxides and there is no real advantage in most cases unless one starts with an insoluble amine such as tris- (hydroxymethyl)aminomethane and this does not apply in the present case.

In any event, as is well known the oxyethylation of polyamines proceeds as readily as the oxypropylation, and this applies also to oxybutylation, particularly if the straight chain butylene oxide isomers are employed. See, for example, U. S. Patents Nos. 2,679,511, 2,679,512, 2,679,513, 2,679,514, and 2,679,515, all dated May 25, 1954, to De Groote.

It is not believed any examples are necessary to illustrate such well known procedure but for purpose of illustration the following are included:

Example laa The reaction vessel employed was a stainless steel autoclave with the usual devices for heating, heat control, stirrer, inlet, outlet, etc., which is conventional in this type of apparatus. The capacity was approximately 4 liters. The stirrer was operated at a speed of approximately 250 R. P. M. There were charged into the autoclave 500 grams of diethylene triamine, 300 grams of xylene, and 15 grams of sodium methylate. The autoclave was sealed, swept with nitrogen gas and stirring started immediately and heat applied. The temperature was allowed to rise to approximately C. At this particular time the addition of propylene oxide was started. Propylene oxide was added continuously at such speed that it was absorbed by the reaction as added. The amount added in this operation was 1500 grams The time required to add the propylene oxide was 2%. hours. During this period the temperature was maintained at 138 to 154 C.,' using cooling water through the inner coils when necessary and otherwise applying heat if required. The maximum pressure during the reaction Was 52 pounds per square inch. Ignoring the xylene and sodium methylate and considering only diethylene triamine for convenience, the resultant product represents 3 parts by weight of propylene oxide to one part by weight of diethylene triamine. The xylene present represented approximately .6 part by weight.

Example 2cm scribed as random oxyalkyiation insofar that one cannot determine the exact location of the propylene oxide or ethylene oxide groups. In such instances the procedure again is identically the same as previously described and,

5 as a matter of fact, I have used such methods in con- The reaction mass of Example laa was transferred to HectiOn With diethylenfi tl'iaminea larger autoclave (capacity '15 liters). Without adding Actually, diethylene triamine at times may contain a any more solvent or any more xylene the procedure wa trace of moisture. My preference is to prepare the solurepeated so as to add another 1500 grams of propylene tion with an excess of xylene andv distill off a part of the oxide under substantially the same operating conditions Xy so as to remove y trace of w r nd hen flush but requiring about 3 hours for the addition. At the end Out the mass with nitrogen- Even there y be a of this step the ratio represented approximately 6 t 1 few tenths of a percent of moisture remain although at (ratio propylene oxide to diethylene triarnine). times examination indicates at the most it is merely a Example 3aa trace As previously pointed out the simplest procedure of In a third step, instead of adding 1500 grams of all is to prepare a binary reaction product of diethylene propylene oxide to the product of Example laa, 1625 triamine and ethylene oxide on the one hand or diethylene grams were added. The reaction slowed up and required triamine and propylene oxide on the other hand, and approximately 6 hours, using the same operating temperareact with the other oxide. Note line CC-DD which tures and pressures. The ratio at the end of the third step indicates that in the binary reaction product obtained was 9.25 parts by weight of propylene oxide per weight from diethylene: triamine and ethylene oxide one employs of diethylene triamine. approximately 66.6% to 96.5% of ethylene oxide andapproximately 3.5% to 33.4% of diethylene triarnine. Example Similarly, if one refers to the line AA-BB it means one would employ from 1.95% of diethylene triamine up At the end of t thud Step, .(Example 351) the l to 14.3% of diethylene triamine and from 85.7% of clave was opened and an additional 5 grams of sodium propylene oxide to 9805970 of Propylene oxide methylate added the autoclavqflushed out as i and In other operations I have proceeded to do as follows: the founh and final oxyalkylauon completed 1625 Mixed the diethylene triamine with an aromatic petrograms of pfoPylene oxlde i the oxyalkylanon was leum solvent and with powdered caustic soda. I have complete wlthm 3% hour? usmg the same temperature stirred this mixture at 125 to 130 C. for a short period P and pressure as previously" F the end of the reac' of time, approximately one-half hour, flushed out with the represerfted approxlmately .Parts of nitrogen, and then subjected to vacuum so as to eliminate P i i Oxide by Welght to one pan Qf diethylene any moisture. I then started to oxypropylate and coni i L tinued until oxypropylation was complete and then havlflg obtamgdfloxypmpylated (ll-ethylene. mamme the: immediately followed with ethylene oxide. In these exproducs wme Sublected to ogiyethylation m a P amplesthe amount of materials used are indicated in comparable to the oxyethylation of triethanolamine, or d h t f D M for that matter, in the same way that oxypropylated poun an m eac ms o mime a i a e 81 1 toclave was used. Although the oxyalkylation started sucrose 1s suo ected to oxyethylation m the manner 40 an described in U. S. Patent No. 2,652,394 dated 3eptember unde Vacuum maxlmum F f was 15 1953, to De Groote Indeed, the procedure is about 10 to l5 pounds. An efiic1ent agitating device was paratively simple for the reason that one is working with used and Surfing was PP P Y 9 a liquid and also that ethylene oxide is more reactive than Thesfi datfl g nlne oXyalkylationsare included in propylene oxide. As a result, using the same amount of Table 1, Immediately followlng- The 11mg PeflOdS are catalyst one can oxyethylate more rapidly and usually at ShOWB- lllddentallyi I have repeated these Same p 3 lower pressure tions using ethylene oxide first and then propylene oxide The same procedure using diethylene triamine in and I have also mixed the two oxides and completed the xylene was employed in connection with ethylene oxide same nine oxyalkylations under substantially the same and the same mixture on a percentage basis was obtained conditions.

TABLE 1 High- Diethylene boiling Caustic Propylene Ethylene Time, Temp, Maximum Ex. No. triamine, aromatic soda, lbs. oxide, lbs. oxide, hrs. 0. press, lbs. lbs. petroleum lbs. per sq. in.

solvent, lbs.

as in the above examples where propylene oxide and diethylene triamine were used.

In the preceding procedures one oxide has been added and then the other. One need not follow this procedure. The oxides can be mixed together in suitable proportions and subsequently subjected to joint oxyalkylation so as to obtain products coming within the specified limits. In such instances, of course, the oxyalkylation may be de- TABLE II Tertiary mixture, percent basis Binary intermediate mixtures, percent basis Points on boundary Di- Propyl- Ethyl- Di- Propyl- Dl- Ethylof area ethylene ene ene ethylene ene ethylene ene trlamine oxide oxide iamine oxide triamine oxide 1. 75 88. 25 10.0 1. 95 98.05 14. 9 85. 1 1.75 50.0 48. 25 3. 38 96. 62 3. 5 96.5 5.0 75. 20.0 6. 24 93. 76 20.0 80. 0 5.0 55.0 40.0 8. 32 91. 68 11.1 88. 9 10.0 70. 0 20. 0 12. 87. 5 33. 4 66. 6 10.0 60.0 30. 0 14.3 85. 7 25.0 75.0 4. 72 76. 4 18. 88 5. 8 94. 2 20.0 80. 0 3. 62 78. 8 18. 4. 42 95. 58 13. 1 86. 9 3. 07 66. 3 30. 63 4. 43 95. 57 9. 1 90. 9 2.84 83.0 14. 16 3. 51 96. 49 16. 7 83. 3 2. 66 57. 5 39. 84 4. 42 95. 58 6. 93. 75 2. 48 72. 6 24. 92 3. 3 96. 7 9. 04 9D. 96 2. 21 64. 7 33.09 3. 3 96. 7 6. 26 93. 74 2.16 81.5 16.54 2. 58 97. 42 11. 55 88. 45 1. 97 74. 5 23. 53 2. 58 97.42 7. 73 92. 27 4.0 61.0 35.0 6. 17 93. 93 10.28 89. 72 1. 8 83.0 16.0 2. 12 97. 88 10. 1 89. 9 7. 0 70. 0 23. 0 9. 1 89. 9 23. 76; 65 8.0 '57. 0 35.0 12.3 87. 7 18. 6 8l. 4 9. O 65. O 26. 0 12. 15 87. 85 25. 7 74. 3

As previously pointed out, the oxyalkylation of diethylene triamine or similar hydroxylated monoor polyamine has been described in the literature and is described also in detail above. All one need do is employ such conventional oxyalkylation procedure to obtain products corresponding to the compositions as defined. Attention is again directed to the fact that one need not add the entire amount of either oxide at one time but that a small portion of one could be added and then another small portion of the other, and the process repeated. For purpose of illustration I have prepared examples in three different ways corresponding to the compositions on the drawing. In the first series propylene oxide and ethylene oxide were mixed; this series is indicated as Aa, Ba, etc., through and including 14a; in the second series propylene oxide was used first followed by ethylene oxide and this series is indicated as Aa, Bb, etc., through and including 145; and finally in a third series, ethylene oxide was used first followed by propylene oxide and this series is indicated as Ac, Bc, etc., through and including 14c. This relationship is shown in Table III.

TABLE III Composition Composition Composition where oxides where propylwhere ethyl- Composition corresponding are mixed ene oxide ene oxide to following point prior to oxyused first folused first folalkylation lowed by ethlowed by proylene oxide pylone oxide Aa Ab Ac Ba B5 B0 Ca Cb On Da Db Dc Ea Eb Ec Fa F5 F0 1a lb 10 2a 2b 20 3a 3b 30 4a 4b 5a 5b 6a 6b 7a 7b 7c 8a 8b 86 9a 9b 96 10a 10b 100 11a 11b 12a 12b 1311 135 11a 14b 14c The products obtained by the above procedure usually show some color varying from a light amber to a pale straw. They can be bleached in the usual fashion using bleaching clays, charcoal, or an organic bleach, such-as peroxide or peracetic acid, or the like.

There are certain variants which can be employed without detracting from the metes and bounds of the invention, but for all practical purposes there is nothing to be gained by such variants and the result is merely increased cost. For instance, any one of the two oxides can be replaced to a minor percentage and usually to a very small degree, by oxide which would introduce substantially the same group along with a side chain, for instance, one could employ glycidyl methyl ether, glycidyl ethyl ether, glycidyl isopropyl ether, glycidyl butyl ether or the like.

Increased branching also may be eflected by the'use of an imine instead of a glycide, or a methyl glycide. Thus one can use ethylene imine or propylene imine in the same way described for glycide or methyl glycide. An additional eifect is obtained due to the basicity of the nitrogen atom. The same thing is true as far as the inclusion of nitrogen atoms if one uses a compound of the kind previously described such as a dialkylaminoepoxypropane. Excellent products are obtained by reacting diethylene triamine with one to 5 moles of ethylene imine and then proceeding in the same manner herein described. In the hereto appended claims reference has been made to glycol ethers of diethylene triamine. Actually it well may be that the products should be referred to as polyol ethers of diethylene triamine in order to emphasize the fact that the final products of reaction have more than two hydroxyl radicals. However, the products may be considered as hypothetically derived by reaction of diethylene triamine with the glycols, such as ethylene glycol, butylene glycol, propylene glycol, or polyglycols. For this reason there seems to be a preference to use the terminology glycol ethers of diethylene triamine.

In a trapezoid such as A, B, D, C, the area can be divided conveniently into five portions by first drawing two lines from the shorter of the two parallel sides perpendicular so as to intersect the other longer parallel line in two places, thus dividing the trapezoid into two triangles and a rectangle. The rectangle then obviously can be divided into three portions of the same size by drawing two additional lines, all of which is shown in the drawing on a larger scale and in dotted lines only. In the hereto attached claims the area within the upper apex of the trapezoid refers to the area within such upper triangle; the area within the lower apex of the trapezoid refers to such'lower triangle. The area in the center of the trapezoid refers to the area defined by the middle rectangle. The area of one rectangle is defined by being between the upper apex and the center rectangle, and the other by being between the lower apex and the center rectangle, all of which is perfectly plain by reference to the drawing. An attempt to draw additional lines and to number them in the same trapezoid A, B, D, C, would only tend towards confusion'and thus the present means is being employed to point out the variousareas which, in turn, appear in the sub-generic claims hereto appended. Thus in the drawing, the area designated V corresponds to the area within the upper triangle, the area W corresponds to the area within the lower triangle, the area X corresponds to that of the middle rectangle, and the areas Y and Z correspond to those of the other rectangles.

PART 3 As to the use of conventional demulsifying agents, reference is made to U. S. Patent No. 2,626,929, dated January 27, 1953, to De Groote, and particularly to Part 3. Everything that appears therein applies with equal force and efiect to the instant process, noting only that where reference is made to Example 13b in said text beginning in column 15 and ending in column 18, reference should be to Example 5b herein described.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A process for breaking petroleum emulsions of the Water-in-oil type characterized by subjecting the emulsion to a demulsi-fying agent including a cogeneric mixture of a homologous series of glycol ethers of diethylene triamine; said cogeneric mixture being derived exclusively from diethylene triamine, propylene oxide and ethylene oxide in such weight proportion so the average composition of said cogeneric mixture stated in terms of the initial reactants lies approximately within the trapezoid of the accompanying drawing in which the minimum diethylene triamine content is at least 1.75% and which trapezoid is identified by the fact that its area lies within the straight lines A, B, F, E.

2. The process of claim 1 with the proviso that oxyalkylation takes place in presence of an alkaline catalyst.

3. The process of claim 1 with the proviso that oxyalkylation takes place in presence of an alkaline catalyst and that at least part of the propylene oxide is added first.

4. The process of claim 1 with the proviso that oxyalkylation takes place in presence of an alkaline catalyst and that all the propylene oxide is added first.

5. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to a demulsifying agent including a cogeneric mixture of a homologous series of glycol ethers of diethylene triamine; said cogeneric mixture being derived exclusively :from diethylene triamine, propylene oxide and ethylene oxide in such weight proportion so the average composition of said cogeneric mixture stated in terms of initial reactants lies approximately Within the trapezoid of the accompanying drawing in which the minimum diethylene triamine content is at least 1.75% and which trapezoid is identified by the fact that its area lies within the straight lines A, B, D, C; with the proviso that all the propylene oxide is added first in the presence of an alkaline catalyst.

6. The process of claim 5 with the proviso that the reactant composition approximates a point in the area corresponding with V within the upper apex of the trapezoid A, B, D, C. p

7. The process of claim 5 with the proviso that the reactant composition approximates a point in the area corresponding with W within the lower apex of the trapezoid A, B, D, C.

8. The process of claim 5 with the proviso that the reactant composition approximates a point in the area corresponding with X of the central part of the trapezoid A, B, D, C.

9. The process of claim 5 with the proviso that the reactant composition approximates a point in the area corresponding with Y between the central part of the trapezoid A, B, C, D, and the upper apex.

10. The process of claim 5 with the proviso that the reactant composition approximates a point of the area corresponding with Z between the central Part of the trapezoid A, B, D, C, and the lower apex.

11. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to a demu-lsifying agent including a cogeneric mixture of a homologous series of glycol ethers of diethylene triamine; said cogeneric mixture being derived exclusively from diethylene triamine, propylene oxide and ethylene oxide in such weight proportion so the average composition of said cogeneric mixture stated in terms of the initial reactants lies approximately within the trapezoid in the accompanying drawing in which the minimum diethylene triamine content is at least 1.75 and which trapezoid is identified by the fact that its area lies within the straight lines A, B, F, E; with the proviso that the hydrophile properties or said cogeneric mixture in an equal weight of xylene are sufficient to produce an emulsion when said xylene solution is shaken vigorously with one to three volumes of Water.

12. The process of claim 11 with the proviso that oxyalkylation takes place in presence of an alkaline catalyst. I

13. The process of claim 11 with the proviso that oxyalkylation takes place in presence of an alkaline catalyst and that at least part of the propylene oxide is added first.

14. The process of claim 11 with the proviso that oxya-lkylation takes place in presence of an alkaline catalyst and that all the propylene oxide is added first.

15. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to a demulsifying agent including a cogeneric mixture of a homologous series of glycol ethers of diethylene triamine; said cogeneric mixture being derived exclusively from diethylene triamine, propylene oxide and ethylene oxide in such weight proportion so the average composition of said cogeneric mixture stated in terms of initial reactants lies approximately within the trapezoid of the accompanying drawing in which the minimum diethylene triamine content is at least 1.75% and which trapezoid is identified by the fact that its area lies within the straight lines A, B, D, C; with the proviso that all the propylene oxide is added first in the presence of an alkaline catalyst; with the further proviso that the hydrophi-le properties of said cogeneric mixture in an equal weight of xylene are sufficient to produce an emulsion I when said xylene solution is shaken vigorously with one to three volumes of water.

16. The process of claim 15 with the proviso that the reactant composition approximates a point in the area corresponding with V within the upper apex of the trapezoid A, B, D, C.

17. The process of claim 15 with the proviso that the reactant composition approximates a point in the area corresponding with W within the lower apex of the trapezoid A, B, D, C.

18. The process of claim 15 with the proviso that the reactant composition approximates a point in the area corresponding with X of the central part of the trapezoid A, B, D, C.

19. The process of claim 15 with the proviso that the reactant composition approximates a point in the area corresponding with Y between the central part of the trapezoid A, B, D, C, and the upper apex.

20. The process of claim 15 with the proviso that the reactant composition approximates a point in the area corresponding with Z between the central part of the trapezoid A, B, D, C, and the lower apex.

References Cited in the file of this patent UNITED STATES PATENTS Huscher et a1. Aug. 18, 1953 

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPE CHARACTERIZED BY SUBJECTING THE EMULSION TO A DEMULSIFYING AGENT INCLUDING A COGENERIC MIXTURE OF A HOMOLOGOUS SERIES OF GLYCOL ETHERS OF DIETHYLENE TRIAMINE; SAID COGENERIC MIXTURE BEING DERIVED EXCLUSIVELY FROM DIETHYLENE TRIAMINE, PROPYLENE OXIDE AND ETHYLENE OXIDE IN SUCH WEIGHT PROPORTION SO THE AVERAGE COMPOSTION OF SAID COGENERIC MIXTURE STATED IN TERMS OF THE INITIAL REACTANTS LIES APPROXIMATELY WITHIN THE TRAPEZOID OF THE ACCOMPANYING DRAWING IN WHICH THE MINIMUM DIETHYLENE TRIAMINE CONTENT IS AT LEAST 1.75% AND WHICH TRAPEZOID IS IDENTIFIED BY THE FACT THAT ITS AREA LIES WITHIN THE STRAIGHT LINES A,B,F,E. 